1. Field of the Invention
The present invention relates to a power conversion apparatus including a capacitor and a heat dissipation member for cooling the capacitor.
2. Description of Related Art
There is known a power conversion apparatus that includes a capacitor and a heat dissipation member for cooling the capacitor, and performs power conversion between DC power and AC power. For example, refer to Japanese Patent Application Laid-open No. 2001-352023. In this power conversion apparatus, the capacitor and the heat dissipation member are pressed in the direction in which they are arranged by a pressing member such as a flat spring, to ensure a contact pressure between the capacitor and the heat dissipation member for increasing the efficiency of cooling the capacitor.
However, there is still room for improvement in increasing the efficiency of cooling the capacitor in the above conventional power conversion apparatus as explained below. The capacitor includes a capacitor element, an electrode part formed in the capacitor element, and a bus bar connected to the electrode part. The capacitor element includes a dielectric body made of resin or ceramic material, and a metal layer formed on the surface of the dielectric body. When a ripple current flows through the metal layer, heat occurs due to resistance of the metal layer. This power conversion apparatus has a structure in which the capacitor is cooled directly by the heat dissipation member. Accordingly, since the heat occurring in the metal layer is blocked by the dielectric body, it is difficult to transfer the heat to the heat dissipation member efficiently. Hence, this power conversion apparatus has a problem in that it is difficult to sufficiently increase the efficiency of cooling the capacitor element.